An Update on the Inflammatory Response after Endovascular Repair for Abdominal Aortic Aneurysm

Can HALP score predict post-contrast acute kidney injury and 6-year mortality in patients undergoing endovascular abdominal aneurysm repair?

BackgroundThe aim of this study is to investigate the relationship between HALP score and post-contrast acute kidney injury (PC-AKI) and average 6-year mortality in patients undergoing endovascular abdominal aortic aneurysm repair (EVAR).Methods125 patients who underwent EVAR between January 2015 and December 2020 were included in our study. HALP score was calculated with the formula "hemoglobin × albumin × lymphocyte count/platelet count." In the first phase of the study, two groups were developed: those who developed PC-AKI and those who did not. In the second stage, statistical analysis was performed by creating two groups: average 6-year mortality and survivors group.ResultsHALP score was found to be lower in the PC-AKI group [26.12 (14-61.54) versus 40.53 (7.22-103.61); p < .001]. Low HALP score was found to be both a dependent and independent predictor of the development of PC-AKI (p = .019). HALP score was also found to be lower in the mortality group compared to the survivors [28.97 (12.6-103.61) versus 40.81 (7.22-99) p = .004]. Low HALP score was found to be only a dependent predictor of mortality. The development of PC-AKI was found to be an independent predictor of mortality (p = .042).ConclusionsThe HALP score, which can be calculated with a simple formula, can be used to predict PC-AKI and medium-long-term mortality in EVAR patients.

Impact of post-implantation syndrome on outcomes in acute type B aortic syndrome patients undergoing endovascular repair

Background: The aim of this study was to explore the impact of post-implantation syndrome (PIS) on prognosis outcomes in individuals with type B acute aortic syndrome (AAS) undergoing thoracic endovascular aortic repair (TEVAR). Patients and methods: Data from type B AAS individuals who underwent TEVAR from January 2014 to April 2021 were retrospectively reviewed. Study subjects were divided into PIS and non-PIS (nPIS) groups and postoperative clinical outcomes were analyzed. Results: Our study cohort of 74 individuals with type B AAS included 40 aortic dissection (AD), 30 intramural hematoma (IMH), 4 penetrating aortic ulcer (PAU). The incidence of PIS was 14.9%. No statistically significant differences were found in baseline characteristics. The left subclavian artery (LSCA) reconstruction was performed more frequently among the PIS group (45.5% vs 9.5%, p=.008). Major adverse events (MAE) tended to be more frequent in the PIS group, but the difference was not significant (27.3% vs 22.2%, p=.707). At 2-year follow-up, results were comparable between the two groups. Kaplan-Meier analysis showed that PIS was not associated with a higher incidence of mortality, endoleak, new-onset AD, or stroke. A baseline neutrophil-to-lymphocyte ratio (NLR) >10.3 was associated with greater incidence of MAE. In individuals with IMH, better aortic remodeling evaluated by lower total aortic diameter/true lumen diameter (TAD/TLD) was achieved in the nPIS group (1.23±0.10 vs 1.43±0.07, p<.001), and a TAD/TLD ratio >1.32 was associated with significantly more MAE. Cox multivariate regression analysis also showed that a postoperative TAD/TLD ratio >1.32 was an independent risk factor for MAE (OR, 11.36; 95% CI, 1.53-84.26; p=.017). Conclusions: PIS was associated with a trend toward a higher incidence of MAE after TEVAR. In individuals with IMH, a TAD/TLD ratio >1.32 was an independent predictor of postoperative MAE.

Evaluation of selected parameters of inflammation, coagulation system, and formation of extracellular neutrophil traps (NETs) in the perioperative period in patients undergoing endovascular treatment of thoracoabdominal aneurysm with a branched device (t-Branch)

Extracellular Neutrophils Traps (NETs) and their formation, known as NETosis, have become pivotal in the pathogenesis of aortic aneurysm development. This study investigates the NETosis markers with the assessment of selected parameters of inflammation and coagulation system in patients with thoracoabdominal aortic aneurysms in the pre-and postop period undergoing t-Branch stent-graft implantation. The study included 20 patients with thoracoabdominal aortic aneurysms. Three markers double-stranded DNA (dsDNA), single-stranded DNA (ssDNA), and citrullinated H3 histones (Cit-H3) were tested at three-time points from patients' blood. The parameters of NETosis, inflammation, and coagulation system were examined in the preoperative period (within 24 h before surgery) and in the postoperative period (on the 3rd and 5th postoperative day). Free-circulating DNA (cfDNA) was isolated from the blood using the MagMAXTM Cell-Free DNA Extraction Kit. Double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA) were then quantified using the Qubit dsDNA HS Assay Kit and the Qubit ssDNA Assay Kit. Cit-H3 concentration was determined by enzyme immunoassay ELISA (Cayman). The results revealed the significance of NETs secretion in response to the complex processes after stent-graft implantation. All NET markers increased shortly after surgery, with histones being the first to return to preoperative levels. The lack of normalization of dsDNA and ssDNA levels to preoperative levels by the last postoperative blood collection demonstrates NETs reorganization. The increase in the number of neutrophils was not related to the expansion of postoperative NETosis. The study reveals a new marker of NETosis, ssDNA, that has not been studied so far. The implantation of a stent graft in a patient with TAAA triggers an inflammatory response manifested by an increase in inflammatory parameters. One of the hallmarks of inflammation is the activation of neutrophil extracellular traps.

Repair of Abdominal Aortic Aneurysms: JACC Focus Seminar, Part 1

Abdominal aortic aneurysms (AAAs), defined by an aortic diameter >3 cm, affect >1 million people in the United States. Risk factors for AAA include male sex, family history of AAA, smoking, Caucasian ethnicity, and age. Patients with known AAA should undergo regular surveillance via ultrasonography. Medical management, including smoking cessation and blood pressure management, is recommended for asymptomatic patients who do not meet the threshold for intervention. Repair options include endovascular aortic repair and open surgical repair, with good outcomes in long-term follow-up. Men with AAA >5.5 cm and women with AAA >5.0 cm in general should undergo elective repair. Medical management, including smoking cessation and blood pressure management, is recommended for asymptomatic patients who do not meet the threshold for intervention.

Exploring the Effect and Mechanism of Si-Miao-Yong-An Decoction on Abdominal Aortic Aneurysm Based on Mice Experiment and Bioinformatics Analysis

Background

Abdominal aortic aneurysm (AAA) is a fatal disease characterized by high morbidity and mortality in old population. Globally, effective drugs for AAA are still limited. Si-Miao-Yong-An decoction (SMYAD), a traditional Chinese medicine (TCM) formula with a high medical value, was reported to be successfully used in an old AAA patient. Thus, we reason that SMYAD may serve as a potential anti-AAA regime.

Objective

The exact effects and detailed mechanisms of SMYAD on AAA were explored by using the experimental study and bioinformatics analysis.

Methods

Firstly, C57BL/6N mice induced by Bap and Ang II were utilized to reproduce the AAA model, and the effects of SMYAD were systematically assessed according to histology, immunohistochemistry, and enzyme-linked immunosorbent assay (ELISA). Then, network pharmacology was applied to identify the biological processes, pathways, and hub targets of SMYAD against AAA; moreover, molecular docking was utilized to identify the binding ability and action targets.

Results

In an animal experiment, SMYAD was found to effectively alleviate the degree of pathological expansion of abdominal aorta and reduce the incidence of Bap/Ang II-induced AAA, along with reducing the damage to elastic lamella, attenuating infiltration of macrophage, and lowering the circulating IL-6 level corresponding to the animal study, and network pharmacology revealed the detailed mechanisms of SMYAD on AAA that were related to pathways of inflammatory response, defense response, apoptotic, cell migration and adhesion, and reactive oxygen species metabolic process. Then, seven targets, IL-6, TNF, HSP90AA1, RELA, PTGS2, ESR1, and MMP9, were identified as hub targets of SMYAD against AAA. Furthermore, molecular docking verification revealed that the active compounds of SMYAD had good binding ability and clear binding site with core targets related to AAA formation.

Conclusion

SMYAD can suppress AAA development through multicompound, multitarget, and multipathway, which provides a research direction for further study.

Single centre experience with Excluder® stent graft; 17-year outcome

BACKGROUND

Endovascular abdominal aortic aneurysm repair (EVAR) has become a mainstay of abdominal aorta aneurysm treatment. Long term follow-up on specific stent grafts is needed.

PATIENTS AND METHODS

This study included 123 patients (104 men; mean age 73.0 years, range 51-89) with abdominal aorta aneurysm, treated with Excluder^® stent graft between October 2002 and June 2008. Periprocedural and follow-up data were retrieved by reviewing the records of our institution, while time and cause of death were retrieved from the National Institute of Public Health. If an abdominal aortic aneurysm rupture was listed as the cause of death, records were retrieved from the institution that issued the death certificate. Our primary goal was to assess the primary technical success rate, type 1 and type 2 endoleak, reintervention free survival, 30-day mortality, the overall survival and aneurysm rupture-free survival.

RESULTS

The median follow-up was 9.7 years (interquartile range, 4.6-13.8). The primary technical success was 98.4% and the 30-day mortality accounted for 0.8%. Secondary procedures were performed in 29 (23.6%) patients during the follow-up period. The one-, five-, ten-, fifteen- and seventeen-year overall survival accounted for 94.3%, 74.0%, 47.2%, 35.8% and 35.8%, while the aneurysm-related survival was 98.4%, 96.3%, 92.6%, 92.6%, 92.6%. In seven (5.7%) patients, abdominal aortic rupture was found as the primary cause of death during follow-up.

CONCLUSIONS

Our data showed that EVAR with Excluder^® stent graft offers good long-term results. More than 75% of patients can be treated completely percutaneously. Late ruptures do occur in the first ten years, raising awareness about regular medical controls.

Incidence and risk factors of post implantation syndrome after elective endovascular aortic aneurysm repair

BACKGROUND

Post implantation syndrome (PIS) represents an acute phase systemic inflammatory response following endovascular aortic aneurysm repair (EVAR). Our objective was to investigate the risk factors associated with the manifestation and severity of PIS with various available stent-grafts.

MATERIALS AND METHODS

We performed a retrospective analysis of prospectively collected data covering the period 2016 - 2020. 191 patients were included. Body temperature was recorded regularly and blood sample was obtained daily. The imaging protocol included computed tomography aortoiliac angiography before surgery and one month after. The volumes of pre-existing and new-onset mural thrombus were calculated in a semiautomated fashion. Five abdominal aortic stent-graft devices were used: Endurant™ ΙΙ, Anaconda™, Treo®, E-tegra® and AFX® 2. Subgroup analysis was performed between woven polyester and ePTFE lined devices.

RESULTS

The incidence of PIS was 21.5%. No significant differences were observed regarding demographics, risk factors, aneurysm anatomy or operative data. The amount of preexisting and new-onset mural thrombus were not related with PIS (p=0.117 and p=0.096). PIS incidence in the polyester subgroup was 24.2%, significantly higher compared to 8.3% in the ePTFE subgroup. In-subgroup analysis revealed that the use of Anaconda™ was associated with the higher frequency (61.1%, p=0.021). Multivariate logistic regression showed that polyester was the single factor significantly associated with PIS (hazard ratio=2.6, p=0.043), as opposed to the new onset thrombus (hazard ratio=1.29, p=0.101).

CONCLUSIONS

PIS is not uncommon and should be taken into consideration in patients presenting with fever after EVAR. The endograft's liner material seems to play the primordial role, with woven polyester to be attributed with significantly higher incidence.

Long Term Outcomes of Post-Implantation Syndrome After Endovascular Aneurysm Repair

OBJECTIVE

The aim of this study was to investigate the association between post-implantation syndrome (PIS) and long term outcomes, with emphasis on cardiovascular prognosis.

METHODS

One hundred and forty-nine consecutive patients undergoing EVAR in a tertiary institution were previously included in a study investigating the risk factors and short term consequences of PIS (defined as tympanic temperature ≥ 38°C and CRP > 10 mg/L, after excluding complications with an effect on inflammatory markers). This study was based on a prospectively maintained database. Survival status was derived from inquiry of civil registry database information and causes of death from the Dutch Central Bureau of Statistics. The primary endpoint was cardiovascular events. Secondary endpoints were overall and specific cause mortality (cardiovascular, ischaemic heart disease, AAA, and cancer related mortality). Aneurysm sac dynamics and occurrence of endoleaks were also analysed. Survival estimates were obtained using Kaplan-Meier plots and a multivariable model was constructed to correct for confounders.

RESULTS

The PIS incidence was 39% (58/149). At the time of surgery, patients had a mean age of 73 ± 7 years and were predominantly male. There were no baseline differences between the PIS and non-PIS groups. The median follow up was 6.4 years (3.2 - 8.3), similar in both groups (p = .81). There was no difference in cardiovascular events for PIS and non-PIS patients (p = .63). However, Kaplan-Meier plots suggest a trend towards a higher rate of cardiovascular events in PIS patients during the first years: freedom from cardiovascular events at one year was 94% vs. 89% and at three years 90% vs. 82%. No differences were found in overall and specific cause mortality. There was a higher rate of type II endoleaks for non-PIS patients (28% vs. 9%, p = .005). Sac dynamics were similar in both groups.

CONCLUSION

The results suggest that PIS is not associated with a statistically significantly higher risk of cardiovascular events. PIS had no impact on mortality. Lastly, PIS patients had fewer type II endoleaks, but sac dynamics were analogous.

Association of Neutrophil-Lymphocyte and Platelet-Lymphocyte Ratio with Adverse Events in Endovascular Repair for Abdominal Aortic Aneurysm

The association of chronic inflammatory markers with the clinical outcome after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) was investigated. We included 230 patients, treated electively with EVAR. The values of neutrophil–lymphocyte ratio (NLR) and platelet–lymphocyte ratio (PLR) were measured pre- and postoperatively. Any major adverse cardiovascular event (MACE) and acute kidney injury (AKI) were recorded. Adverse events occurred in 12 patients (5.2%). Seven patients suffered from MACE and five from AKI. Median NLR and PLR values were significantly increased after the procedure (NLR: from 3.34 to 8.64, p < 0.001 and PLR: from 11.37 to 17.21, p < 0.001). None of the patients or procedure characteristics were associated with the occurrence of either a MACE or AKI. Receiver operating characteristic curve analysis showed that postoperative NLR and PLR were strongly associated with AKI. A threshold postoperative NLR value of 9.9 was associated with the occurrence of AKI, with a sensitivity of 80% and specificity of 81%. A threshold postoperative PLR value of 22.8 was associated with the occurrence of AKI, with a sensitivity of 80% and specificity of 83%. Postoperative NLR and PLR have been associated with the occurrence of AKI after EVAR for AAA.

[18F-fluorodeoxyglucose PET/CT in the diagnosis of vascular graft infection]

OBJECTIVE

To investigate diagnostic role of 18F-fluorodeoxyglucose PET/CT in patients with suspected vascular graft (VG) infection.

MATERIAL AND METHODS

A prospective analysis included data of 30 PET/CT examinations for suspected infection of aortic VG (n=27) and bypass grafts (n=3) after surgical treatment (median 48 months). In 77% (23/30) of cases, the diagnosis was initially «possible» (n=11) or «rejected» (n=12) in accordance with common diagnostic criteria. All PET/CT results were verified by clinical, laboratory and intraoperative («=20) data. VG infection was confirmed in 18 patients and ruled out in 12 cases.

RESULTS

PET/CT confirmed VG infection in 94% (17/18) and excluded in 50% (6/12) of cases. False PET/CT results were obtained in 23% (7/30) cases: false positive in 6 cases and false negative in 1 case. Thus, sensitivity, specificity and diagnostic accuracy of PET/CT were 94%, 50% and 77%, respectively; positive and negative predictive value - 74% and 86%. PET/CT results allowed correct reclassifying 33% (10/30) of cases. VG infection was confirmed in 73% (8/11) of patients with initially «possible» diagnosis and excluded in 17% (2/12) of patients with initially «rejected» infection. Moreover, whole body PET/CT revealed unknown inflammation foci outside VG in 73% (22/30) of cases. These data were applied to correct treatment approach in 80% (24/30) of cases.

CONCLUSION

Our results showed high efficacy of 18F-fluorodeoxyglucose PET/CT in the diagnosis of VG infection. Despite low specificity, this technique has high sensitivity and accuracy that allowed reclassifying 33% of cases.

Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm: A Comprehensive Review

Abdominal aortic aneurysm (AAA) can be defined as an abnormal, progressive dilatation of the abdominal aorta, carrying a substantial risk for fatal aneurysmal rupture. Endovascular aneurysmal repair (EVAR) for AAA is a minimally invasive endovascular procedure that involves the placement of a bifurcated or tubular stent-graft over the AAA to exclude the aneurysm from arterial circulation. In contrast to open surgical repair, EVAR only requires a stab incision, shorter procedure time, and early recovery. Although EVAR seems to be an attractive solution with many advantages for AAA repair, there are detailed requirements and many important aspects should be understood before the procedure. In this comprehensive review, fundamental information regarding AAA and EVAR is presented.

Cardiac biomarkers improve prediction performance of the combination of American Society of Anesthesiologists physical status classification and Americal College of Surgeons National Surgical Quality Improvement Program calculator for postoperative mortality in elderly patients: a pilot study

BACKGROUND

Our previous research has shown American Society of Anaesthesiologists physical status classification (ASA) score and Americal College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) calculator to have the most accuracy in the prediction of postoperative mortality.

AIMS

The aim of our research was to define the most reliable combination of cardiac biomarkers with ASA and ACS NSQIP.

METHODS

We have included a total of 78 patients. ASA score has been determined in standard fashion, while we used the available interactive calculator for the ACS NSQIP score. Biomarkers BIRC5, H-FABP, and hsCRP have been measured in specialized laboratories.

RESULTS

All of the deceased patients had survivin (BIRC5) > 4.00 pg/ml, higher values of H-FABP and hsCRP and higher estimated levels of ASA and ACS NSQIP (P = 0.0001). ASA and ACS NSQIP alone had AUC of, respectively, 0.669 and 0.813. The combination of ASA and ACS NSQIP had AUC = 0.841. Combination of hsCRP with the two risk scores had AUC = 0.926 (95% CI 0.853-1.000, P < 0.0001). If we add three cardiac biomarkers to this model, we get AUC as high as 0.941 (95% CI 0.876-1.000, P < 0.0001). The correction of statistical models with comorbidities (CIRS-G score) did not change the accuracy of prediction models that we have provided.

DISCUSSION

Addition of ACS NSQIP and biomarkers adds to the accuracy of ASA score, which has already been proved by other authors.

CONCLUSION

Cardiac biomarker hsCRP can be used as the most reliable cardiac biomarker; however, the "multimarker approach" adds the most to the accuracy of the combination of clinical risk scores.

Nonsteroidal anti-inflammatory drug use is a risk factor for early Type II endoleak after endovascular abdominal aortic repair

Objectives

Type II endoleak is a problem after endovascular abdominal aneurysm repair. Preoperative risk factors for Type II endoleak include anatomical factors in the lumbar artery and inferior mesenteric artery; however, preventable postoperative risk factors are unknown. Postimplantation syndrome is associated with lower incidence of Type II endoleak. Therefore, we focused on inflammation, and our aim was to investigate nonsteroidal anti-inflammatory drugs as a postoperative risk factor for Type II endoleak.

Methods

This was a retrospective study of patients with aortic aneurysm who underwent endovascular aneurism repair at the Department of Cardiovascular Surgery, Beppu Medical Center, Oita, Japan, from January 2011 to August 2018. Clinical characteristics were retrieved from patients’ medical records and included age, sex, body mass index, smoking history, comorbidities, treatment devices, medications, and perioperative information, including postimplantation syndrome. Postimplantation syndrome was defined as body temperature >38.5°C with 12,000/dL white blood cells or >10.0 mg/dL C-reactive protein. The primary outcome was the presence or absence of Type II endoleak assessed on the first postoperative enhanced computed tomography scan. Risk factors for Type II endoleak were assessed. Results and conclusions: Of the eligible 84 patients, 20 (24%) had Type II endoleak identified in the first enhanced computed tomographic scans after endovascular aneurism repair. Nonsteroidal anti-inflammatory drug use (odds ratio (OR): 21.2; 95% confidence interval (95% CI): 1.5–308.4; P = 0.026), cerebrovascular disease (OR: 7.27; 95% CI: 1.06–49.99; P = 0.044), and body mass index <22 kg/m2 (OR: 17.3; 95% CI: 2.1–141.8; P = 0.008) were independent risk factors for Type II endoleak after endovascular aneurism repair. Comparing the rate of Type II endoleak among patients who did not receive nonsteroidal anti-inflammatory drugs within 24 h after endovascular aneurism repair, patients who first used nonsteroidal anti-inflammatory drugs 12–24 h after endovascular aneurism repair, and those who received nonsteroidal anti-inflammatory drugs within 12 h after endovascular aneurism repair, we found a significant difference among the groups (4%, 18%, 45%, respectively; P = 0.001). Nonsteroidal anti-inflammatory drug use within 24 h after endovascular aneurism repair is a risk factor for Type II endoleak. We should know nonsteroidal anti-inflammatory drugs within 24 h after endovascular aneurism repair can be a risk of Type II endoleak.

How to recognize stent graft infection after endovascular aortic repair: the utility of 18F-FDG PET/CT in an infrequent but serious clinical setting

OBJECTIVE

To evaluate the diagnostic performance of ¹⁸F-FDG PET/CT in the detection of stent graft infection (SGI).

METHODS

In a retrospective study, two nuclear medicine physicians have independently analyzed 17 ¹⁸F-FDG PET/CT examinations performed for clinical suspicion of SGI. The images were evaluated for the uptake pattern and intensity, and by the maximum standard uptake value (SUV_max), the target-to-background ratio with blood pool (TBR_BP) and liver uptake (TBR_hep) as a reference. The SGI was defined as the presence of focal hyperactivity with an intensity exceeding hepatic uptake. CT images were independently assessed for signs of SGI. Clinical review of all further patients' data served as the standard of reference.

RESULTS

Nine cases were established as SGI by the clinical review. PET/CT correctly diagnosed SGI in eight and yielded a sensitivity of 89% and specificity of 100%. The mean SUV_max, TBR_BP, and TBR_hep values were 9.8 ± 4.0, 6.9 ± 2.6, and 4.6 ± 1.7 in the group of patients with true SGI, and 4.0 ± 1.1, 2.5 ± 0.4 (p < 0.001) and 1.9 ± 0.2 (p < 0.001) in true negative cases, respectively. CT alone showed a sensitivity of 78% and specificity of 100% and was concordant with PET/CT in 14 cases. The best performing threshold values of SUV_max, TBR_BP, and TBR_hep were 5.6, 3.5, and 2.2, respectively.

CONCLUSION

¹⁸F-FDG PET/CT with expert evaluation, semiquantitative and quantitative image analysis with the proposed threshold values for SUV_max, TBR_BP, and TBR_hep has good diagnostic accuracy in the detection of SGI. We propose that visual grading scale for SGI should use hepatic uptake as a visual reference.

Cytokines as biomarkers of inflammatory response after open versus endovascular repair of abdominal aortic aneurysms: a systematic review

The repair of an abdominal aortic aneurysm (AAA) is a high-risk surgical procedure related to hormonal and metabolic stress-related response with an ensuing activation of the inflammatory cascade. In contrast to open repair (OR), endovascular aortic aneurysm repair (EVAR) seems to decrease the postoperative stress by offering less extensive incisions, dissection, and tissue manipulation. However, these beneficial effects may be offset by the release of cytokines and arachidonic acid metabolites during intra-luminal manipulation of the thrombus using catheters in endovascular repair, resulting in systemic inflammatory response (SIR), which is clinically called post-implantation syndrome. In this systematic review we compared OR with EVAR in terms of the post-interventional inflammatory response resulting from alterations in the circulating cytokine levels. We sought to summarize all the latest evidence regarding post-implantation syndrome after EVAR. We searched Medline (PubMed), ClinicalTrials.gov and the Cochrane library for clinical studies reporting on the release of cytokines as part of the inflammatory response after both open/conventional and endovascular repair of the AAA. We identified 17 studies examining the cytokine levels after OR versus EVAR. OR seemed to be associated with a greater SIR than EVAR, as evidenced by the increased cytokine levels, particularly IL-6 and IL-8, whereas IL-1β, IL-10 and TNF-α showed conflicting results or no difference between the two groups. Polyester endografts appear to be positively correlated with the incidence of post-implantation syndrome after EVAR. Future large prospective studies are warranted to delineate the underlying mechanisms of the cytokine interaction in the post-surgical inflammatory response setting.

Acute non-traumatic disease of the abdominal aorta

Acute pathology in the abdominal aorta is associated with significant morbidity and mortality. The most feared complication of abdominal aortic disease is acute rupture in the setting of atherosclerotic abdominal aortic aneurysm. Although frank rupture often is easily diagnosed on CT, other findings such as a hyperattenuating crescent, discontinuous intimal calcium, and draping of the aorta are subtle signs of aneurysm instability. A true aneurysm should be distinguished from a rapidly growing, saccular pseudoaneurysm in the setting of infectious aortitis, as treatment strategy differs. Acute aortic syndrome involving the abdominal aorta, such as dissection and intramural hematoma, often is an extension of thoracic aortic disease, whereas penetrating atherosclerotic ulcers occasionally involve only the abdominal aorta. The goal of treating acute aortic pathology is to repair and prevent rupture, as well as restore and maintain perfusion of the lower extremities, kidneys, and mesentery. However, both open and endovascular repair of the abdominal aorta may become acutely complicated, resulting in compromise of these goals. Examples include aortoenteric fistula, endoleak, anastomotic pseudoaneurysm, graft infection, and thrombosis or kinking of a stent graft resulting in ischemia of the limbs and mesentery.

Systemic inflammatory response syndromes in the era of interventional cardiology

Systemic inflammatory response syndrome (SIRS), initially reported after cardiovascular surgery, has been described after various interventional cardiology procedures, including endovascular/thoracic aortic repair (EVAR/TEVAR), implantation of heart rhythm devices, percutaneous coronary intervention (PCI), electrophysiology procedures (EP), and transcatheter aortic valve implantation (TAVI). In these settings, a comprehensive understanding of the triggers, pathogenesis as well as a common diagnostic/therapeutic algorithm is lacking and will be discussed in this review. SIRS occurs in about 40% and 50% of patients undergoing TEVAR/EVAR and TAVI respectively; it affects 0.1% of patients undergoing implantation of heart rhythm devices. Prevalence is unknown after PCI or EP. Clinical presentation includes fever, dyspnoea/tachypnoea, tachycardia, weakness, chest pain and pericardial/pleural effusion. Several triggers can be identified, related to implanted devices, biomaterial, and procedural aspects (prolonged hypotension, aneurysm thrombus manipulation, active fixation atrial leads, coronary microembolization, balloon dilatation/stent implantantation, contrast medium, coronary/myocardial microperforation). Nonetheless, these triggers share three main pathogenic pathways leading to SIRS clinical manifestations: leucocytes activation, endothelial injury/activation, and myocardial/pericardial injury. Therapy consists of non-steroidal agents, with corticosteroids as second-line treatment in non-responders. Although a benign evolution is reported after implantation of heart rhythm devices, PCI and EP, major adverse events may occur after EVAR/TEVAR and TAVI at short- and mid-term follow up.

Low baseline and subsequent higher aortic abdominal aneurysm FDG uptake are associated with poor sac shrinkage post endovascular repair

PURPOSE

The growth phases of medically treated abdominal aortic aneurysms (AAA) are frequently associated with an ¹⁸F-fluorodesoxyglucose positron emission tomography (FDG-PET) pattern involving low baseline and subsequent higher FDG uptake. However, the FDG-PET patterns associated with the endovascular aneurysm repair (EVAR) of larger AAA are presently unknown. This study aimed to investigate the relationship between serial AAA FDG uptake measurements, obtained before EVAR and 1 and 6 months post-intervention and subsequent sac shrinkage at 6 months, a well-recognized indicator of successful repair.

METHODS

Thirty-three AAA patients referred for EVAR (maximal diameter: 55.4 ± 6.0 mm, total volume: 205.7 ± 63.0 mL) underwent FDG-PET/computed tomography (CT) before EVAR and at 1 and 6 months thereafter, with the monitoring of AAA volume and of a maximal standardized FDG uptake [SUVmax] averaged between the axial slices encompassing the AAA.

RESULTS

Sac shrinkage was highly variable and could be stratified into three terciles: a first tercile in which shrinkage was absent or very limited (0-29 mL) and a third tercile with pronounced shrinkage (56-165 mL). SUVmax values were relatively low at baseline in the 1st tercile (SUVmax: 1.69 ± 0.33), but markedly increased at 6 months (2.42 ± 0.69, p = 0.02 vs. baseline). These SUV max values were by contrast much higher at baseline in the 3rd tercile (SUVmax: 2.53 ± 0.83 p = 0.009 vs. 1st tercile) and stable at 6 months (2.49 ± 0.80), while intermediate results were documented in the 2nd tercile. Lastly, the amount of sac shrinkage, expressed in absolute values or in percentages of baseline AAA volumes, was positively correlated with baseline SUVmax (p = 0.001 for both).

CONCLUSION

A low pre-EVAR FDG uptake and increased AAA FDG uptake at 6 months are associated with reduced sac shrinkage. This sequential FDG-PET pattern is similar to that already shown to accompany growth phases of medically treated AAA.

The role of IL-6 in pathogenesis of abdominal aortic aneurysm in mice

Although the pathogenesis of abdominal aortic aneurysm (AAA) remains unclear, evidence is accumulating to support a central role for inflammation. Inflammatory responses are coordinated by various soluble cytokines of which IL-6 is one of the major proinflammatory cytokines. In this study we examined the role of IL-6 in the pathogenesis of experimental AAA induced by a periaortic exposure to CaCl2 in mice. We now report that the administration of MR16-1, a neutralizing monoclonal antibody specific for the mouse IL-6 receptor, mildly suppressed the development of AAA. The inhibition of IL-6 signaling provoked by MR16-1 also resulted in a suppression of Stat3 activity. Conversely, no significant changes in either NFκB activity, Jnk activity or the expression of matrix metalloproteinases (Mmp) -2 and -9 were identified. Transcriptome analyses revealed that MR16-1-sensitive genes encode chemokines and their receptors, as well as factors that regulate vascular permeability and cell migration. Imaging cytometric analyses then consistently demonstrated reduced cellular infiltration for MR16-1-treated AAA. These results suggest that IL-6 plays an important but limited role in AAA pathogenesis, and primarily regulates cell migration and infiltration. These data would also suggest that IL-6 activity may play an important role in scenarios of continuous cellular infiltration, possibly including human AAA.

The β-d-Endoglucuronidase Heparanase Is a Danger Molecule That Drives Systemic Inflammation and Correlates with Clinical Course after Open and Endovascular Thoracoabdominal Aortic Aneurysm Repair: Lessons Learnt from Mice and Men

Thoracoabdominal aortic aneurysm (TAAA) is a highly lethal disorder requiring open or endovascular TAAA repair, both of which are rare, but extensive and complex surgical procedures associated with a significant systemic inflammatory response and high post-operative morbidity and mortality. Heparanase is a β-d-endoglucuronidase that remodels the endothelial glycocalyx by degrading heparan sulfate in many diseases/conditions associated with systemic inflammation including sepsis, trauma, and major surgery. We hypothesized that (a) perioperative serum levels of heparanase and heparan sulfate are associated with the clinical course after open or endovascular TAAA repair and (b) induce a systemic inflammatory response and renal injury/dysfunction in mice. Using a reverse-translational approach, we assessed (a) the serum levels of heparanase, heparan sulfate, and the heparan sulfate proteoglycan syndecan-1 preoperatively as well as 6 and 72 h after intensive care unit (ICU) admission in patients undergoing open or endovascular TAAA repair and (b) laboratory and clinical parameters and 90-day survival, and (c) the systemic inflammatory response and renal injury/dysfunction induced by heparanase and heparan sulfate in mice. When compared to preoperative values, the serum levels of heparanase, heparan sulfate, and syndecan-1 significantly transiently increased within 6 h of ICU admission and returned to normal within 72 h after ICU admission. The kinetics of any observed changes in heparanase, heparan sulfate, or syndecan-1 levels, however, did not differ between open and endovascular TAAA-repair. Postoperative heparanase levels positively correlated with noradrenalin dose at 12 h after ICU admission and showed a high predictive value of vasopressor requirements within the first 24 h. Postoperative heparan sulfate showed a strong positive correlation with interleukin-6 levels day 0, 1, and 2 post-ICU admission and a strong negative correlation with lactate clearance during the first 6 h post-ICU admission. Moreover, systemic administration of heparanase and heparan sulfate induced an inflammatory response and a small degree of renal dysfunction in mice. In conclusion, these results suggest that heparanase and heparan sulfate exhibit a substantial role as clinically relevant danger molecules and may serve as both, promising biomarkers and therapeutic targets in patients undergoing open or endovascular TAAA repair and, indeed, other conditions associated with significant systemic inflammation.

Protracted refractory pain post-TEVAR: post-implantation syndrome?

Aortic dissection is a life-threatening condition and has one of the highest mortality rates of cardiovascular diseases. It remains a devastating disease; with multiple unanswered questions concerning treatment modalities. The role of thoracic endovascular aortic repair (TEVAR) in these patients; especially those with uncomplicated acute aortic Type B dissections (AAD-B) is especially controversial although it has been shown to have better long-term outcomes compared to medical therapy alone. For those who have TEVAR, up to 60% may develop an acute, transient systemic inflammatory response syndrome that remains vaguely defined. The role of local inflammation in this post-implantation syndrome (PIS) has not been highlighted. We present a case of a 57-year-old male patient with an uncomplicated AAD-B who developed an ‘atypical’ PIS post-TEVAR with severe refractory abdominal pains; leukocytosis and raised C-reactive protein. The role of local inflammation in PIS is highlighted.